Electrodeposition of bright nickel-iron deposits,electrolytes therefor and coating an article with a composite nickel-iron,chromium coating

ABSTRACT

AN AQUEOUS BATH SUITABLE FOR THE ELECTRODEPOSITION OF A BRIGHT IRON-NICKLE ALLOY ELECTRODEPOSITION COMPRISING IRON IONS, NICKEL IONS, AN IRON COMPLEXING AGENT CONTAINING AT LEAST TWO COMPLEXING GROUPS INDEPENDENTLY SELECTED FROM THE GROUP CONSISTING OF CARBOXY AND HYDROXY PROVIDED AT LEAST ONE GROUP IS A CARBOXY GROUP, AND HAVING A PH FROM 2.5 TO 5.5

Unitcd States Patent O ELECTRODEPOSITION OF BRIGHT NICKEL-IRON DEPOSITS, ELECTROLYTES THEREFOR AND COATING AN ARTICLE WITH A COMPOSITE NICKEL-IRON, CI-IROMIUM COATING Richard John Clauss, Allen Park, Robert Arnold Tremmel, Woodhaven, and Norman Charles Adamowicz, Inkster, Mich., assignors to Oxy Metal Finishing Corporation, Warren, Mich.

No Drawing. Continuation-impart of application Ser. No. 268,348, July 3, 1972. This application July 19, 1973, Ser. No. 380,631

Int. Cl. C23b 5/32, 5/50 U.S. Cl. 204-41 13 Claims ABSTRACT OF THE DISCLOSURE An aqueous bath suitable for the electrodeposition of a bright iron-nickel alloy electrodeposit comprising iron ions, nickel ions, an iron complexing agent containing at least two complexing groups independently selected from the group consisting of carboxy and hydroxy provided at least one group is a carboxy group, and having a pH from 2.5 to 5.5.

CROSS-REFERENCE TO RELATED CASES This application is a continuation-in-part of application Ser. No. 268,348, filed July 3, 1972.

BACKGROUND OF THE INVENTION For many years, electrodeposition of nickel has been employed as a substrate for the electrodeposition of chromium in order to impart satisfactory corrosion resistant properties to a metallic surface. Researchers have been attempting to obtain various alloys of nickel in order to decrease the cost of obtaining a satisfactory decorative finish. Iron-nickel deposits have been used previously for the electrodeposition of electromagnetic films. These films are usually extremely thin surfaces and normally are not decorative in character or exposed to corrosive environments. Various references describe alloys of nickel such as that mentioned in Metal Finishing, December 1967, page 67 and following; British specification 312,441; British specification 924,144; British specification 1,039,- 798; British specification 1,105,189; U.S. 2,809,156; U.S. 3,031,386; U.S. 3,032,485; U.S. 3,032,486; U.S. 3,325,259 and U.S.S.R. Pat. 270,429.

SUMMARY OF THE INVENTION It has been found that satisfactory bright iron-nickel alloy deposits can be obtained which are comparable to 100% nickel deposits in brightness, leveling and ductility with good corrosion resistant properties as a substrate for chromium electrodeposition. The iron-nickel alloy bath contains ions of iron and ions of nickel, and an iron complexing agent containing complexing groups such as carboxy and hydroxy groups. When such a bath is used for the electrodeposition of iron-nickel alloys in conjunction with a bath soluble nickel brightener a bright ironnickel alloy deposit is obtained.

DESCRIPTION OF PREFERRED EMBODIMENTS Applicants invention is directed to the electrodeposition of a bright iron-nickel alloy deposit of from 5 to about 50% by weight iron preferabl about 15 to about 35% by weight which can be used as the basis for subsequent electrodeposition of chromium in order to impart desirable decorative and/or corrosion resistant properties to substrates, such as metallic substrates.

The bath and process of the present invention can also be used in the electrodeposition of a nickel-iron alloy for plastics. Normally the plastic substrate such as acryloare nitrile butadiene-styrene, polyethylene, polypropylene, polyvinyl chloride, phenol-formaldehyde polymers is pretreated by applying a conductive metallic deposit onto the plastic substrate such as, nickel or copper. The ironnickel deposit may then be used as a subsequent coating onto the conductive metallic deposit.

The bath that may be employed in the present invention utilizes one or more salts of nickel, one or more salts of iron, and a complexing agent.

In order to introduce iron and nickel ions into the bath, any bath soluble iron or nickel containing compound may be employed providing the corresponding anion is not detrimental to the bath. Preferably inorganic nickel salts may be employed, such as, nickel sulfate, nickel chloride, and the like as well as other nickel materials such as nickel sulfamate and the like. When nickel sulfate salts are used they are normally present in amounts ranging from 40 to 300 grams per liter (calculated as nickel sulfate 6H O); nickel chloride may also be used and is present in an amount ranging from about to 250 grams per liter. The chloride or halide ions are employed in order to obtain satisfactory conductivity of the solution and at the same time to obtain satisfactory corrosion properties of the soluble anodes.

Preferably the inorganic salts of iron are employed, such as, ferrous salts, such as, ferrous sulfate, ferrous chloride, and the like. These salts are present in an amount ranging from about 3 to 60 grams per liter. Other bath soluble iron salts that may be employed, such as, soluble ferrous fluoborate, or sulfamate, and the like.

The iron complexing agent that is employed in the present invention is one that is bath soluble and contains complexing groups independently selected from the group consisting of carboxy and hydroxy provided at least 1 of the complexing groups is a carboxy group and further provided that there are at least two complexing groups. The complexing agent that may be employed is present in amount ranging from about 10 to about grams per liter. Suitable complexing agents are hydroxy substituted lower aliphatic carboxylic acids having from 2 to 8 carbon atoms, from 1 to 6 hydroxyl groups and from 1 to 3 carboxyl groups such as, ascorbic acid, isoascorbic acid, citric acid, malic acid, glutaric acid, gluconic acid, muconic, glutamic, gluheptonate, glycollic acid, aspartic acid and the like as well as amine containing complexing agents, such as nitrilotriacetic acid, ethylene diamine tetra-acetic acid, as well as the water soluble salts thereof such as ammonium and the alkali metal salts such as potassium, sodium, lithium, and the like. It can also be appreciated that the iron may be introduced into the bath as a salt of the complexing agent.

By carboxy is meant the group-COOH. However, it is to be appreciated that in solution, the proton disassociates from the carboxy group and therefore this group is to 'be included in the meaning of carboxy.

The purpose of the complexing agent is to keep the metal ions, in particular, the ferrous and ferric ions in solution. It has been found that as the pH of a normal Watts nickel-plating bath increases above a pH of 3.0, ferric ions tend to precipitate as ferric hydroxide. The complexing agent will prevent the precipitation from taking place and therefore makes the iron and nickel ions available for electrodeposition from the complexing agent.

While the iron is always introduced as the ferrous salt, it has been established that a portion of the iron in solution is almost always oxidized from the ferrous to ferric state. The concentration of ferric ion in solution is determined by a number of factors, and particularly by the operating pH of the solution. The type and amount of anode area in the solution will also affect the relative concentration of ferric ion. We believe this may be due to the oxidizing of ferrous to ferric ion at the anode. Generally speaking, it is found that at least 5% of the total iron in solution is present as ferric ions, and it is preferred that the ferric ion not exceed 30 to 40% of the total iron in the bath, although it has been established in work performed to date that acceptable results may be obtained when even as much as 60% of the iron in the solution is present as ferric ions. It has been observed that the relative concentration of ferric ion will be higher in an air agitated solution than one that is dependent on only cathode agitation. The exact structure which is formed by the interaction of the ferric ion with the complexing agent is not known. The literature reports a number of possible structures under different conditions; for instance, the structure reported in water solution may be different from that determined in biological applications. We also have reason to believe that the structure in a plating solution changes during electrolysis. Regardless of the exact structure, the ferric ion is not precipitated from the solution, as the hydroxide, even at a pH of 5.

Because of the operating parameters employing the complexing agent, the pH of the bath preferably ranges from about 2.5 to about 5.5 and even more preferably about 3 to about 4.6.

The temperature of the bath may range from about 120 F. to about 180 F. preferably about 160 F.

The average cathode current density may range from about to about 70 amps per square foot preferably about 45 amps per square foot.

It is preferred that the complexing agent concentration should be at least three times the total iron ion concentration in the bath. The complexing agent concentration ratio to total iron ion concentration may range from 3 to 50:1.

The bath may also contain various buffers such as boric acid and sodium acetate and the like ranging in amount from about 30' to 60 grams per liter, preferably 40 grams per liter. The ratio of nickel ions to iron ions ranges from about 5 to about 50 to 1.

While the bath may be operated without agitation, various means of agitation may be employed such as mechanical agitation, air agitation, cathode rod movement and the like.

It has been found that various nickel brightening additives may be employed to impart brightness, ductility and leveling to the iron nickel deposits. Suitable additives are the sulfo-oxygen compounds as are described as brighteners of the first class described in Modern Electroplating, published by John Wiley and Sons, second edition, page 272.

The amount of sulfo-oxygen compounds employed in the present invention ranges from about 0.5 to about 10 grams per liter. It has been found that saccharin may be used in amounts ranging from 0.5 to about 5 grams per liter resulting in a bright ductile deposit. When other sulfooxygen compounds are employed, such as, naphthalenetrisulfonic, sulfobenzaldehyde, dibenzenesulfonamide, good brightness is obtained but the ductility is not as good as with saccharin. In addition to the above-sulfo-oxygen compounds that may be used, others are sodium alkyl sulfonate, benzene sulfinates, vinyl sulfonate, beta-styrene sulfonate, cyano alkane sulfonates (having from 1 to 5 carbon atoms).

The bath soluble sulfa-oxygen compound that may be used in the present invention are those such as the unsaturated aliphatic sulfonic acids, mononuclear and binuclear aromatic sulfonic acids, mononuclear aromatic sulfinic acids, mononuclear aromatic sulfonamides and sulfonimides, and the like.

It has also been found that acetylenic nickel brighteners may also be used in amounts ranging from about 10 to about 500 milligrams per liter. Suitable compounds are the acetylenic sulfo-oxygen compounds mentioned in U.S. 2,800,440. These nickel brighteners are the oxygen containing acetylenic sulfo-oxygen compounds. Other acetylenic nickel brighteners are those described in U.S.

3,366,557 such as the polyethers resulting from the condensation reaction of acetylenic alcohols and diols such as, propargyl alcohol, butyndiol, and the like and lower alkylene oxides such as, epichlorohydrin, ethylene oxide, propylene oxide and the like.

It has also been found that nitrogen heterocyclic quaternary or betaine nickel brighteners may also be used in amounts ranging from about 1 to about 50 milligrams per liter. Suitable compounds are those nickel brihgteners described in U.S. 2,647,866 and the nitrogen heterocyclic sulfonates described in U.S. 3,023,151. Preferred compounds described therein are the pyridine quaternaries or betaines or the pyridine sulfobetaines. Suitable quaternaries that may be employed are quinaldine propane sultone, quinaldine dimethyl sulfate, quinaldine allyl bromide, pyridine allyl bromide, isoquinaldine propane sultone, isoquinaldine dimethyl sulfate, isoquinaldine allyl bromide, and the like.

At times the low current density areas are not fully bright. To extend the current density range of the ironnickel bath of the present invention other organic sulfide nickel brighteners are employed in amounts ranging from about 0.5 to about 40 milligrams per liter of the electroplating bath composition. These organic sulfides are of the formula:

where R is hydrogen or a carbon atom of an organic radical, R is nitrogen or a carbon atom of an organic radical and R is a carbon atom of an organic radical. R and R or R may be linked together through a single organic radical.

More specifically, the bath soluble organic sulfide compounds used are 2-amine thiazoles and isothioureas having the formula:

wherein R is selected from H, lower alkyl sulfonic acid groups, aryl sulfonic acid groups, lower alkoxy aryl sulfonic acid groups and the salts thereof;

R and R are selected from H, halogen, lower alkyl groups and the bivalent radical I I I Bio 10 10 B10 in which the R groups are selected from H, halogen and lower alkyl groups; R is selected from the lower alkyl sulfonic acid groups and lower alkyl carboxy acid groups and the salts thereof; and R and R are selected from H, halogen, lower alkyl groups and the bivalent radical in which the R groups are selected from H, halogen and lower alkyl groups.

It is to be appreciated that in referring to halogen, it is intended to include chlorine, bromine, fluorine and iodine, although chlorine is generally preferred. Moreover, where reference is made to lower alkyl or alkoxy groups, it is intended to include groups containing from about 1 to 6 carbon atoms in a straight or branched chain, with from about 1 to 4 carbon atoms being preferred. Additionally, in referring to the sulfonic or carboxy acids and their salts, it is intended to include those sulfonic and carboxy acids which have halogen substituents on their alkyl, alkoxy or aryl groups and wherein the salts are exemplified by the alkali metal salts, sodium, potassium, lithium, cesium and rubidium, particularly sodium. In referring to the bivalent radicals above, a six-membered ring is formed when R and R are joined and a five membered ring is formed when R and R are joined.

Suitable compounds are those of the formulae appearing below.

TABLE I Concentration range (g a liter) 1 no N HC JL-NH:

(3) HC---NH. 0. 001-0. 06

compound (1), 2-aminothiazole and compound (2), 2- aminobenzothiazole can be reacted with bromethane sulfonate, propane sultone, benzyl chloride, dimethylsulfate, diethyl sulfate, methyl bromide, propargyl bromide, ethylene dibromide, allyl bromide, methyl chloro acetate, sulfophenoxyethylenc bromide, the latter, for example, can be reacted with compound 1) to give compound (3), etc., to form compounds that give even improved results over compounds (1) and (2). Also, substituted 2-aminothiazoles and Z-aminobenzothiazoles, such as 2-amino-5- chlorothiazole, 2-amino-4-methylthiazole, etc., can be used instead of compounds (1) and (2). To form compounds such as (5) and (6), thiourea can be reacted with propiolactone, butyrolactone, chloroacetic acid, chloropropionic acid, propane sultone, dimethyl sulfate, etc. Also, phenyl thiourea, methyl thiourea, allyl thiourea and other similar substituted thioureas may be used in the reactions to form compounds similar to types (5) and (6).

It is to be appreciated that the above nickel brighteners must be soluble in the electroplating bath and may be introduced into the bath, when an acid is involved, as the acid itself or as a salt having bath soluble cations, such as ammonium ions of the alkali metal ion, such as, lithium, potassium, sodium, and the like.

It has been found that the use of bright nickel iron deposits of about 20 to 45 iron content function as well or better than bright nickel deposits in certain composite electroplate systems.

In particular, relatively thin coatings of bright nickeliron having less than about 0.'5-mil thickness (such as 0.1-mil thickness) with an alloy content of about 20 to 45% iron, function more effectively than an equivalent bright nickel coating when copper or brass undercoats are employed. In particular, if the iron content is about 35% or more, the alloy deposits corrode more preferentially to copper or brass undercoats than does bright nickel. This action delays penetration to the basis metal.

These bright nickel-iron coatings also function well as the thin top coat on semi-bright sulfur free nickel deposits. The bright nickel-iron is very effective in such a composite electroplate when overplated with microdiscontinuous chromium coatings such as that described in US. Pats. 3,563,864 and 3,151,971-3. The microdiscontinuous chromium coatings may be achieved by thin nickel deposits which induce micro-porosity or microcracking in the chromium or by plating the chromium deposit from a specific solution which deposits a microcracked chromium.

It can be appreciated that the nickel salts may be substituted with minor amounts up to 50% of the nickel salts with cobalt salts in order to achieve different corrosion behavior.

A suitable composition that may be employed in the present invention is as follows:

Complexing agent (g. 'l.) Boric acid Anode current density (a.s t Tleimperature, F D

2.5 to 5.5 3. (H. 2 A itation Air or rod Brightener See abov It is to be appreciated that various other additives may be employed to effect desirable results such as surface active agents to overcome any undesirable problems that may occur in particular situations such as pitting.

When significant amounts of iron are being introduced into the system, it has been found that soluble iron anodes or nickel-iron alloy anodes should be employed. The ratio of nickel to iron in the anode area should be maintained at approximately 4 to 1. Preferably dual (nickel and iron) anodes are used and the iron anodes should be insulated and connected to the anode rail through a highly electrically resistant device such as a nickel-chrome wire or controlled by a separate rheostat to maintain a total current to the iron anodes of about 8 to about 30% preferably about 10% to 25% of the total anode current. Anode bags, filter bags, hoses, tank linings etc. should be those which are generally employed in other bright nickel processes.

EXAMPLE NO. 1

A bright iron-nickel bath was formulated as follows:

Nickel sulfate hexahydrate g./ 1-- 50 Nickel chloride hexahydrate g./l Ferrous sulfate heptahydrate g./l l5 Ammonium hydrogen citrate g./l 26 Boric acid g./l 60 Saccharin g./l 4.5 Allyl sulfonate g./l. 3.75 Butyne diol ethylene oxide (ratio 1.8 moles oxide: 1 mole diol) mg./l 200 Quinaldine propane sultone mg./l.. 10

pH: 4.0. Temperature: 150 F. Agitation: Rod.

Rolled steel panels were plated at 45 ASF and gave full bright lustrous ductile deposits containing 15-20% iron.

EXAMPLE NO 2 Following the procedure of Example No. 1 but containing; 7.5-75 g./l. glycine instead of citrate resulted in the formation of an insoluble complex. No acceptable nickel-iron deposit was obtained.

EXAMPLE NO. 3

Another nickel-iron bath was formulated as follows:

Nickel sulfate hexahydrate g./l 75 Nickel chloride hexahydrate g./l 75 Ferrous sulfate heptahydrate g./l 15 Sodium gluconate g./l 40 Boric acid ...g./l 40 Saccharin g./l 2.5 Allyl sulfonate g./l 6.0 Glycerol ether of butyne diol (adduct of 1.8 moles ethylene oxidezl mole diol) mg./l 50 Glycerol ether of butyne diol sulfonated (same as above adduct except product is sulfonated) mg./l.. 50 Adduct of 1.8 moles epichlorohydrinzl mole propargyl alcohol; product is sulfonated -..mg./l 15 Thiourea S-- acetic acid mg./l 2.5

pH: 3.0. Temp.: 150 F. Agitation: Air.

A test panel (J-steel) plated from this bath gave a bright level deposit with excellent ductility and clean recess areas.

The iron content of the plated deposit was approximately 20-25%.

EXAMPLE NO. 4

' A nickel-iron plating bath having a high iron concentration was tested in a pilot plating laboratory. The composition of the bath was as follows:

G./l. Ni 42.0

H BO 36.0 Na gluconate 65.0 Fe total 5.8 Saccharin 2.5 Allyl sulfonate 6.0

Glycerol ether of butyne diol (see Example No:

3) 0.05 Glycol ether of butyne diol sulfonated (see Example 3) Adduct of ethylene oxide and propargyl alcohol pH: 3.0. Temperature: 155 F.

A I-type steel panel plated at 50 ASF was overall bright, leveled, very ductile, with a part skipped recess area.

0.002 g./l. of dithio dipropane sulfonate was added to the bath and another panel was plated. The resulting deposit was again overall bright, leveled and ductile; however, now the recess areas were clean, covered and bright.

The iron included in these deposits was approximately 38-47%.

8 EXAMPLE N0. 5

A bath was formulated as follows:

Fe total g./1 3.11 Pe g./l 2.83 Fe+ g./l 0.28 Allyl sulfonate g./l 4.5 Saccharin g./l 3 Butyne diol ethylene oxide adduct (1:1.8 mole ratio) mg./l 2.00 Quinaldine propane sultone mg./l 10 NiCl -6H O g./l 101.8 NiSO -6H O g./l 122.7 Ni++ g./l 52.6 Boric acid g./l 59.1 Diamrnonium citrate g./l 26.8

Temperature: F. Agitation: Cathode or rod.

A J-shaped panel was plated at 40 ASF and obtained was a full bright lustrous deposit in the high current density area and a low current density cloud.

Addition of only 50 mg./l. of benzene sulfinate removed the recess cloud completely. The deposits contained 17.5% Fe.

EXAMPLE NO. 6

Two nickel-iron plating solutions were prepared havin the following compositions.

NiSO -6H O 75 F0504 15 H BO 40 Na gluconate 12.5 Na citrate 12.5 Saccharin 3.0 Allyl sulfonate 6.0

Adduct of butyne diol and epichlorohydrin (1.2

moles hydrin:- mole diol); product sulfonated 0.06

Adduct of butyne diol and epichlorohydrin (1.2

moles hydrinzl mole diol); product sulfonated 0.06

Adduct of propargyl alcohol and epichlorohydrin Adduct of butyne diol and epichlorohydrin (1.2

moles hydrinzl mole diol); product sulfonated 0.06 Adduct of propargyl alcohol and epichlorohydrin (1:1 mole ratio); product sulfonated 0.02 Dithiodipropane sulfonate 0.002 Temperature: Agitation: Air.

Test panels were plated from each solution for 10 minutes at 45 ASF. Results showed both deposits to be overall bright with clean recess areas, with Panel A having better leveling than Panel B. Both panels had excellent ductility. As can be seen in Example No. 6 a plurality of complexmg agents may be used to obtain desirable results. It has also been determined that the gluconate complexing agent tends after long periods of electrolysis to form insoluble materials such as nickel salt of a gluconate degradation product. To continue to obtain desirable results a combination of complexing agents may be employed, such as, citrate and gluconate.

While applicants do not wish to be bound by a particular theory, it would appear that one possible structure which results from the complexing of ferric ions in solution is the formation of a hydrated ferric gluconate, as is postulated by Chaberak and Martell in Organic Sequestering Agents, pages 314 and 315, published in 1959 by John Wiley and Son.

There has been disclosed herein numerous changes and modifications in the processes and solutions of this invention, and these and other variations may of course be practiced without departing from the spirit of the invention or the scope of the subjoined claims.

We claim:

1. An aqueous acidic bath suitable for the electrodeposition of a bright iron-nickel electrodeposit onto a substrate susceptible to corrosion, which comprises iron ions and nickel ions, the ratio of nickel ions to iron ions being from about to about 50 to 1 and wherein at least 5% of total iron in solution is present as ferric ions, a bath soluble primary nickel brightener including 0.5 to g./l. of a sulfo-oxygen compound, and 10 to 100 g./l. of a bath soluble non-reducing complexing agent which is a saturated aliphatic carboxylic acid having 1 to 3 carboxyl groups, 2 to 8 carbon atoms and 1 to 6 bydroxyl groups, the ratio of complexing agent to iron ions concentration in the bath being from 3 to about 50 to 1 and the bath having a pH from 3.0 to about 4.6.

2. The bath of claim 1, wherein the complexing agent is gluconic acid.

3. The bath of claim 1, wherein the sulfo-oxygen brightener is saccharin.

4. The bath of claim 1, further comprising an acetylenic nickel brightener present in an amount ranging from about 10 to 500 mg./l.

5. A process for producing a bright iron-nickel alloy electrodeposit comprising passing a current through the bath of claim 1 and electrodepositing an iron-nickel alloy onto a cathodic surface.

6. The process of claim 5, wherein the complexing agent is citric acid.

7. The process of claim 5, wherein the complexing agent is gluconic acid.

8. The process of claim 5, wherein the sulfo-oxygen is saccharin.

9. The process of claim 5, further comprising an acetylenic nickel brightener present in an amount ranging from about 10 to 500 mg./l.

10. The process of claim 5, wherein the minimum thickness of the iron-nickel deposit is 0.1 mil.

11. A process for producing an iron-nickel alloy, chromium coated article compriing electrodepositing an ironnickel alloy onto a substrate in the bath of claim 1 and subsequently electrodepositing chromium upon the ironnickel coating.

12. The process of claim 11, wherein the chromium deposit is a micro-cracked deposit.

13. The process of claim 11, wherein the chromium deposit is a micro-porous deposit.

References Cited UNITED STATES PATENTS 2,712,522 7/1955 Kardos et al. 204-49 2,900,707 8/1959 Brown 204-41 XR 3,031,386 4/1962 Tsu et al. 204-43 T 3,239,437 3/ 1966 Stephen 204-43 T 3,271,274 9/1966 Di Guilio et al 204-43 T 3,354,059 11/1967 Koretzky 204-43 T XR 3,380,151 4/1968 Parsons 204--48 XR 3,496,074 2/1970 Welling 204-48 XR FOREIGN PATENTS 871,276 6/1961 Great Britain 204-49 1,229,625 9/1960 France 204-43 T OTHER REFERENCES C & EN, pp. and 81, Jan. 21,1963. J. C. Merriam, The Iron Age, pp. 73-76, Sept. 22, 1966.

P. Elsie et al., Metal Finishing, pp. 67-69, November 1966.

GERALD L. KAPLAN, Primary Examiner US. Cl. X.R. 204-43 T UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3 3,896,429

DATED Aprll 23, 1974 INVENTOR(S) Richard J. Clauss et a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below; Column 3, Line 59 "alkyl" should read allyl.

Column 4, Line 9 "brihgteners" should read --brighteners-.

Column 4, Lines 43-44 R N u C S R R I 8 H Q Should read:

C S R N H Column 5, Line 40 "0.10" should read 0.0l-.

Column 5, Line 74 "of" should read or.

Column 8, Line 42 After the colon, delete and insert -l--.

Column 8, Line 42 "product sulfonated" should read -product hydrolyzed-.

Signed and Scaled this Sixteenth Day of November 1976 [SEAL] Arrest;

RUTH "4 c. MARSHALL DANN Aneslmg Office ('lmmiflilmr flarents and Trademarks 

